Process for preparing 1-acetyl-6-oxo-8alpha-methyl-3,4,6,7,8,8alpha-hexahydronaphthalene



PROCESS FOR PREPARING l-ACETYL 6 OXO-Sa- Q IETHY L 3,4,6,7,8,8aHEXAHYDRONAPHTHA- ENE Melvin S. Newman and Sambasiva Swaminathau,Columbus, Ohio, assignors to The Ohio State University ResearchFoundation, Columbus, Ohio, a corporation of Ohio No Drawing. Originalapplication January 18, 1952, Se-

rial No. 267,097. Divided and this application August 12, 1953, SerialNo. 377,460

1 Claim. (Cl. 260 586) The present invention relates to the preparationof a novel organic compound and is more particularly concerned with thepreparation of 1-acetyl-6-oxo-8a-methyl-3,4,6,7,8,Sa-hexahydronaphthalene. The present application is a divisionof our copending application, Serial Number 267,097, filed January 18,1952, now abandoned, which is a continuation-in-part of application,Serial Number 242,982, filed August 21, 1951 and which subsequentlyissued as Patent 2,614,123 on October 14, 1952.

The invention disclosed in this application relates to new compositionsof matter.

One object of this invention is to produce a new composition of matterconsisting of a 1-acetyl-6-oxo-8a-methyl-3,4,6,7,8,Sa-hexahydronaphthalene. This new compound is usefulas an intermediate for the total synthesis of steroids and so far as weknow has never heretofore been conceived or synthesized. As a startingpoint for this compound, We can use 8a-methyll,2,3,4,6,7,8,8a octahydro1 ethynyl 1 ,8 hydroxy- 6-oxonaphthalene.

The starting compound is disclosed and the process of making it isdisclosed in application for United States Patent Serial No. 218,410,now abandoned. In order to produce the new composition of matter, wereact the above described starting material with formic acid bydissolving it in formic acid and refluxing. The starting compound (asstated in said copending application Serial No. 218,410) has a formulaas follows:

-GECH Also as stated in said copending application Serial No. 218,410,the compound has a melting point at 171.5- 172.5 and was analyzed tohave C, 76.3-76.4 and H, 7.8. Inasmuch as we have found a secondepimeror geometric form of the compound, said second form having a lowermelting point, the above starting compound is considered as the B epimerand based on the analogy to configuraa tions that have been ascribed toethynyl alcohols prepared from 17-keto steroids, is considered to havethe valence bond of the hydroxyl group above the plane of the paper.

The resulting acetyl compound has a formula as follows:

It will be noted that not only are the ethynyl and hydroxyl radicals (i.e.

converted into the acetyl radical but also the 1 and 2 carbons becomeunsaturated through the introduction of a double bond between them.

Following is an example of the process we have used to produce our novelcomposition of matter.

Example I 1-acetyl-6oxo-8a-methyl-3 ,4,6,7,8,8a-hexahydronaphthaleneHat: 0

A solution ofSa-methyl-1,2,3,4,6,7,8,8a-octahydrol-ethynyl-1-B-hydroxy-6-oxonaphthalene(M. P. 171-172". 2.8 g.) in formic acid (92%; 16 ml.) was refluxed for 2hours. The reaction mixture was then poured into water and the aqueoussuspension extracted with ether twice. The ether extract aftersuccessive washings with dilute sodium hydroxide solution, water andsaturated sodium chloride solution was dried over anhydrous sodiumsulfate and later concentrated. A brown viscous residue remained and waschromatographed on a column of deactivated alumina (Fisher) prepared bytreatment with methanol and subsequent drying for 6 hours at 130.

The reaction product was dissolved in dry benzene (100 ml.) and passedthrough the column. After most of the benzene had passed through, thecolumn was eluted with ether (200 ml.) and the ether solutionconcentrated. A viscous liquid remained and solidified on cooling. Thesolid was crystallized from ether; M. P. -93. A recrystallization fromether yielded the desired acetyl compound having the formula shownabove, melting at 92-93.

References Cited in the file of this patent UNITED STATES PATENTS Newmanet a1. Oct. 14, 1952 OTHER REFERENCES Cassidy: Adsorption andChromatography, 1951, pg. 259.

